Role of metaplasia during gastric regeneration

An antibiotic-free platform for eliminating persistent Helicobacter pylori infection without disrupting gut microbiota

Helicobacter pylori (H. pylori) infection remains the leading cause of gastric adenocarcinoma, and its eradication primarily relies on the prolonged and intensive use of two antibiotics. However, antibiotic resistance has become a compelling health issue, leading to H. pylori eradication treatment failure worldwide. Additionally, the powerlessness of antibiotics against biofilms, as well as intracellular H. pylori and the long-term damage of antibiotics to the intestinal microbiota, have also created an urgent demand for antibiotic-free approaches. Herein, we describe an antibiotic-free, multifunctional copper-organic framework (HKUST-1) platform encased in a lipid layer comprising phosphatidic acid (PA), rhamnolipid (RHL), and cholesterol (CHOL), enveloped in chitosan (CS), and loaded in an ascorbyl palmitate (AP) hydrogel: AP@CS@Lip@HKUST-1. This platform targets inflammatory sites where H. pylori aggregates through electrostatic attraction. Then, hydrolysis by matrix metalloproteinases (MMPs) releases CS-encased nanoparticles, disrupting bacterial urease activity and membrane integrity. Additionally, RHL disperses biofilms, while PA promotes lysosomal acidification and activates host autophagy, enabling clearance of intracellular H. pylori. Furthermore, AP@CS@Lip@HKUST-1 alleviates inflammation and enhances mucosal repair through delayed Cu2+ release while preserving the intestinal microbiota. Collectively, this platform presents an advanced therapeutic strategy for eradicating persistent H. pylori infection without inducing drug resistance.

Role and research progress of spasmolytic polypeptide‑expressing metaplasia in gastric cancer (Review)

Gastric cancer ranks as one of the most prevalent cancers worldwide. While the incidence of gastric cancer in Western countries has notably diminished over the past century, it continues to be a leading cause of cancer‑related mortality on a global scale. The majority of gastric cancers in humans are attributed to chronic Helicobacter pylori infection and the progression of gastric cancer is often preceded by gastritis, atrophy, metaplasia and dysplasia. However, the precise mechanisms underlying the development of gastric cancer remain ambiguous, including the formation of gastric polyps and precancerous lesions. In humans, two types of precancerous metaplasia have been identified in relation to gastric malignancies: Intestinal metaplasia and spasmolytic polypeptide‑expressing metaplasia (SPEM). The role of SPEM in the induction of gastric cancer has gained recent attention and its link with early‑stage human gastric cancer is increasingly evident. To gain insight into SPEM, the present study reviewed the role and research progress of SPEM in gastric cancer.

Gastroprotective effect of eupatilin, a polymethoxyflavone from Artemisia argyi H.Lév. & Vaniot, in ethanol-induced gastric mucosal injury via NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia argyi H.Lév. & Vaniot (AA) has been extensively utilized as an important medicine and food homology in China, Japan, Korea, and eastern parts of Russia, owing to its pharmacological effects, which include anti-inflammatory, antibacterial, antitussive, and antiallergic properties. Despite the extract of AA can significantly alleviate gastric mucosal injury, its precise material basis for effectiveness is not yet clear. As one of the polymethoxy flavonoids with high content in AA, the gastroprotective activity and molecular mechanism of eupatilin (EUP) require further investigation.

AIM OF THE STUDY

This study aims to investigate the gastroprotective effects and possible mechanisms of EUP by using an ethanol-induced gastric mucosal injury model in rats.

MATERIALS AND METHODS

EUP was isolated from 95% ethanol extract of AA using a systematic phytochemical method. The gastroprotective activity of EUP was evaluated using a male SD rat model with ethanol-induced gastric mucosa injury. Histopathology evaluation of gastric tissues was performed using hematoxylin and eosin (H&E) staining. The levels of cytokines in the plasma and tissues were tested using the ELISA kits, while western blot analysis was employed to assess the expressions of COX-2, iNOS, and NF-κB pathway proteins.

RESULTS

A sufficient amount of EUP was obtained from AA through chromatographic methods and identified by NMR experiment. In vivo, experimental results proved that EUP could significantly alleviate pathological features, increased SOD, GSH, and IL-10 levels, and decreased the contents of MDA, TNF-α, IL-1β, and IL-6. Further in vitro and in vivo Western blot experimental results showed that EUP significantly down-regulates the expressions of the NF-κB signal pathway to relieve inflammatory responses.

CONCLUSION

This study demonstrated that EUP could exert gastroprotective effects by inhibiting inflammation, enhancing gastric mucosal defense, and ameliorating oxidative stress, which is beneficial for providing scientific data for the development of gastric protection.

Targeting NF-κB/COX-2 signaling by soyasaponin I alleviates diclofenac-induced gastric ulceration in male albino rats

Gastric ulceration is a prevalent worldwide clinical presentation due to altered gastric defense mechanisms. Nonsteroidal anti-inflammatory drugs are one of the common causes of gastric ulcers mediated by the release of inflammatory mediators. The study aimed to investigate the potential protective effect of soyasaponin I (soya) against diclofenac (DIC)-induced gastric ulcer in rats and to highlight the underlying mechanisms. The experiment was conducted on 40 male Wistar albino rats, equally distributed into five groups: control, DIC-induced ulcer (9 mg/kg/d, orally, twice daily for 3 days), ulcer/soya-, ulcer/ranitidine-, and ulcer/soya/selective nuclear factor kappa B inhibitor (JSH-23)-treated groups. The doses of soya, ranitidine, and JSH were 20, 25, and 5 mg/kg/d, respectively, given orally. Gastric specimens were prepared for gene and histological study and for biochemical analysis of gastric prostaglandin E2 (PGE2), oxidative markers, and inflammatory cytokines. The gastric samples were formalin-fixed, paraffin-embedded, and subjected to hematoxylin and eosin (H&E), PAS staining, and immunohistochemical assay for identification of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), and proliferation marker (Ki67) expressions. The findings revealed decreased gastric PGE2 and altered inflammatory and oxidative markers in the ulcer model group. The H&E staining showed mucosal injury characterized by mucosal surface defects and inflammatory cell infiltrations. The polymerase chain reaction (PCR) and immunohistochemistry demonstrated an upregulation of NF-κB and COX-2 expression at gene/protein levels; meanwhile, Ki67 downregulation. The soya-treated group showed maintained biochemical, histological, and PCR findings comparable to the ranitidine-treated group. The JSH-23-treated group still showed partial gastric protection with biochemical and immunohistochemical changes. Soyasaponin I ameliorated DIC-induced gastric ulcers by targeting the COX-2 activity through modulation of NF-κB signaling.

Transcription Factor Zbtb20 as a Regulator of Malignancy and Its Practical Applications

Zbtb20 (zinc finger and BTB domain-containing protein 20) is a transcription factor with a zinc finger DNA binding domain and a BTB domain responsible for protein-protein interaction. Recently, this TF has received attention because new data showed its pivotal involvement in normal neural development and its regulatory effects on proliferation and differentiation in different tissues. Zbtb20 was shown to increase proliferation and migration and confer resistance to apoptosis in the contexts of many malignant tumors like hepatocellular carcinoma, non-small-cell lung carcinoma, gastric adenocarcinoma, glioblastoma multiforme, breast cancer, and acute myeloid leukemia. The involvement of Zbtb20 in tumor biology is best studied in hepatocellular carcinoma, where it is a promising candidate as an immunohistochemical tumor marker or may be used in patient screening. Here we review the current data connecting Zbtb20 with malignant tumors.

SOX9 Governs Gastric Mucous Neck Cell Identity and Is Required for Injury-Induced Metaplasia

BACKGROUND & AIMS

Acute and chronic gastric injury induces alterations in differentiation within the corpus of the stomach called pyloric metaplasia. Pyloric metaplasia is characterized by the death of parietal cells and reprogramming of mitotically quiescent zymogenic chief cells into proliferative, mucin-rich spasmolytic polypeptide-expressing metaplasia (SPEM) cells. Overall, pyloric metaplastic units show increased proliferation and specific expansion of mucous lineages, both by proliferation of normal mucous neck cells and recruitment of SPEM cells. Here, we identify Sox9 as a potential gene of interest in the regulation of mucous neck and SPEM cell identity in the stomach.

METHODS

We used immunostaining and electron microscopy to characterize the expression pattern of SRY-box transcription factor 9 (SOX9) during murine gastric development, homeostasis, and injury in homeostasis, after genetic deletion of Sox9 and after targeted genetic misexpression of Sox9 in the gastric epithelium and chief cells.

RESULTS

SOX9 is expressed in all early gastric progenitors and strongly expressed in mature mucous neck cells with minor expression in the other principal gastric lineages during adult homeostasis. After injury, strong SOX9 expression was induced in the neck and base of corpus units in SPEM cells. Adult corpus units derived from Sox9-deficient gastric progenitors lacked normal mucous neck cells. Misexpression of Sox9 during postnatal development and adult homeostasis expanded mucous gene expression throughout corpus units including within the chief cell zone in the base. Sox9 deletion specifically in chief cells blunts their reprogramming into SPEM.

CONCLUSIONS

Sox9 is a master regulator of mucous neck cell differentiation during gastric development. Sox9 also is required for chief cells to fully reprogram into SPEM after injury.

Characterizing the specific mechanism of series processed Coptidis Rhizoma by multi-organ metabolomics combined with network pharmacology and molecular docking

BACKGROUND

After being processed with different excipients, the clinical application of Coptidis Rhizoma (CR) is differentially investigated. However, the underlying mechanism and material basis are not clear, and there is a lack of attention to the collaborative working mode of herbal medicine during exploration.

PURPOSE

To characterize the specific mechanism of wine/zingiberis rhizoma recens/euodiae fructus processed CR (wCR/zCR/eCR) and to investigate the role of excipients during processing.

METHODS

The multi-organ metabolomics approach was employed to explore the target organs of wCR/zCR/eCR and multiple pathways being triggered in each organ. The tissue distribution of CR and wCR/zCR/eCR components was compared to indicate the material basis of efficacy change after processing. Further, the network pharmacology study coupled with experimental validation was conducted to support metabolomic research and predicted active ingredients and core targets, and the molecular docking coupled with binding test was performed to identify the binding between active ingredient and core target.

RESULTS

The multi-organ metabolomics and network pharmacology study elucidated the intervening effect of wCR on heart/lung, zCR on stomach/colon, and eCR on liver/colon/stomach. Combined with molecular docking, binding test and tissue distribution studies, the specific mechanism was as follows: the wine made iso-quinoline alkaloids in CR more likely to accumulate in heart/lung, thus triggering the core targets of PTGS2, NOS2, ESR1 and SLC6A4 in heart/lung, and thereby highlighting the detoxifying and cardiopulmonary protective effect of wCR. The zingiberis rhizoma recens and euodiae fructus made organic acids in CR more likely to accumulate in stomach/colon and liver/colon/stomach respectively, thus triggering the core targets of ACTB, TNF and PRKCA in stomach/colon, the core targets of ACTB, TNF, PRKCA and GPT in stomach/colon/liver, and thereby highlighting the improving effect of zCR/eCR on digestive function.

CONCLUSION

Iso-quinoline alkaloids were the material basis of CR for anti-inflammation, and organic acids were mainly responsible for regulating gastrointestinal function. Due to the influence of excipients on the accumulation tendency of CR components, the differentially highlighted application of wCR/zCR/eCR was achieved. These findings propose a novel strategy for processing mechanism research.

Gastric immune homeostasis imbalance: An important factor in the development of gastric mucosal diseases

The gastric mucosal immune system is a unique immune organ independent of systemic immunity that not only maintains nutrient absorption but also plays a role in resisting the external environment. Gastric mucosal immune disorder leads to a series of gastric mucosal diseases, including autoimmune gastritis (AIG)-related diseases, Helicobacter pylori (H. pylori)-induced diseases, and various types of gastric cancer (GC). Therefore, understanding the role of gastric mucosal immune homeostasis in gastric mucosal protection and the relationship between mucosal immunity and gastric mucosal diseases is very important. This review focuses on the protective effect of gastric mucosal immune homeostasis on the gastric mucosa, as well as multiple gastric mucosal diseases caused by gastric immune disorders. We hope to offer new prospects for the prevention and treatment of gastric mucosal diseases.

The immune microenvironment in gastric adenocarcinoma

Like most solid tumours, the microenvironment of epithelial-derived gastric adenocarcinoma (GAC) consists of a variety of stromal cell types, including fibroblasts, and neuronal, endothelial and immune cells. In this article, we review the role of the immune microenvironment in the progression of chronic inflammation to GAC, primarily the immune microenvironment driven by the gram-negative bacterial species Helicobacter pylori. The infection-driven nature of most GACs has renewed awareness of the immune microenvironment and its effect on tumour development and progression. About 75-90% of GACs are associated with prior H. pylori infection and 5-10% with Epstein-Barr virus infection. Although 50% of the world's population is infected with H. pylori, only 1-3% will progress to GAC, with progression the result of a combination of the H. pylori strain, host susceptibility and composition of the chronic inflammatory response. Other environmental risk factors include exposure to a high-salt diet and nitrates. Genetically, chromosome instability occurs in ~50% of GACs and 21% of GACs are microsatellite instability-high tumours. Here, we review the timeline and pathogenesis of the events triggered by H. pylori that can create an immunosuppressive microenvironment by modulating the host's innate and adaptive immune responses, and subsequently favour GAC development.

A comparative study of vestibular improvement and gastrointestinal effect of betahistine and gastrodin in mice

Betahistine and gastrodin are the first-line medications for vestibular disorders in clinical practice, nevertheless, their amelioration effects on vestibular dysfunctions still lack direct comparison and their unexpected extra-vestibular effects remain elusive. Recent clinical studies have indicated that both of them may have effects on the gastrointestinal (GI) tract. Therefore, we purposed to systematically compare both vestibular and GI effects induced by betahistine and gastrodin and tried to elucidate the mechanisms underlying their GI effects. Our results showed that betahistine and gastrodin indeed had similar therapeutic effects on vestibular-associated motor dysfunction induced by unilateral labyrinthectomy. However, betahistine reduced total GI motility with gastric hypomotility and colonic hypermotility, whereas gastrodin did not influence total GI motility with only slight colonic hypermotility. In addition, betahistine, at normal dosages, induced a slight injury of gastric mucosa. These GI effects may be due to the different effects of betahistine and gastrodin on substance P and vasoactive intestinal peptide secretion in stomach and/or colon, and agonistic/anatgonistic effects of betahistine on histamine H1 and H3 receptors expressed in GI mucosal cells and H3 receptors distributed on nerves within the myenteric and submucosal plexuses. Furthermore, treatment of betahistine and gastrodin had potential effects on gut microbiota composition, which could lead to changes in host-microbiota homeostasis in turn. These results demonstrate that gastrodin has a consistent improvement effect on vestibular functions compared with betahistine but less effect on GI functions and gut microbiota, suggesting that gastrodin may be more suitable for vestibular disease patients with GI dysfunction.

Gastric epithelial histology and precancerous conditions

The most common histological type of gastric cancer (GC) is gastric adenocarcinoma arising from the gastric epithelium. Less common variants include mesenchymal, lymphoproliferative and neuroendocrine neoplasms. The Lauren scheme classifies GC into intestinal type, diffuse type and mixed type. The WHO classification includes papillary, tubular, mucinous, poorly cohesive and mixed GC. Chronic atrophic gastritis (CAG) and intestinal metaplasia are recommended as common precancerous conditions. No definite precancerous condition of diffuse/poorly/undifferentiated type is recommended. Chronic superficial inflammation and hyperplasia of foveolar cells may be the focus. Presently, the management of early GC and precancerous conditions mainly relies on endoscopy including diagnosis, treatment and surveillance. Management of precancerous conditions promotes the early detection and treatment of early GC, and even prevent the occurrence of GC. In the review, precancerous conditions including CAG, metaplasia, foveolar hyperplasia and gastric hyperplastic polyps derived from the gastric epithelium have been concluded, based on the overview of gastric epithelial histological organization and its renewal.

Revisiting therapeutic strategies for ovarian cancer by focusing on redox homeostasis

Recent advances in molecular genetics have expanded our understanding of ovarian cancer. High levels of reactive oxygen species (ROS) and upregulation of antioxidant genes are common characteristic features of human cancers. This review reconsiders novel therapeutic strategies for ovarian cancer by focusing on redox homeostasis. A literature search was performed for preclinical and clinical studies published between January 1998 and October 2021 in the PubMed database using a combination of specific terms. ROS serves a central role in tumor suppression and progression by inducing DNA damage and mutations, genomic instability, and aberrant anti- and pro-tumorigenic signaling. Cancer cells increase their antioxidant capacity to neutralize the extra ROS. Additionally, antioxidants, such as CD44 variant isoform 9 (CD44v9) and nuclear factor erythroid 2-related factor 2 (Nrf2), mediate redox homeostasis in ovarian cancer. Furthermore, studies conducted on different cancer types revealed the dual role of antioxidants in tumor progression and inhibition. However, in animal models, genetic loss of antioxidant capacity in the host cannot block cancer initiation and progression. Host-derived antioxidant systems are essential to suppress carcinogenesis, suggesting that antioxidants serve a pivotal role in suppressing cancer development. By contrast, antioxidant activation in cancer cells confers aggressive phenotypes. Antioxidant inhibitors can promote cancer cell death by enhancing ROS levels. Concurrent inhibition of CD44v9 and Nrf2 may trigger apoptosis induction, potentiate chemosensitivity and enhance antitumor activities through the ROS-activated p38/p21 pathway. Antioxidants may have tumor-promoting and -suppressive functions. Therefore, an improved understanding of the role of antioxidants in redox homeostasis and developing antioxidant-specific inhibitors is necessary for treating ovarian cancer.

mAb Das-1 recognizes 3'-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia

INTRODUCTION

Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett's esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive.

METHODS

In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA.

RESULTS

The epitope recognized by mAb Das-1 is 3'-Sulfo-Lewis A/C (3'-Sulfo-LeA/C). 3'-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation.

DISCUSSION

3'-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.

Follow the Metaplasia: Characteristics and Oncogenic Implications of Metaplasia's Pattern of Spread Throughout the Stomach

The human stomach functions as both a digestive and innate immune organ. Its main product, acid, rapidly breaks down ingested products and equally serves as a highly effective microbial filter. The gastric epithelium has evolved mechanisms to appropriately handle the myriad of injurious substances, both exogenous and endogenous, to maintain the epithelial barrier and restore homeostasis. The most significant chronic insult that the stomach must face is Helicobacter pylori (Hp), a stomach-adapted bacterium that can colonize the stomach and induce chronic inflammatory and pre-neoplastic changes. The progression from chronic inflammation to dysplasia relies on the decades-long interplay between this oncobacterium and its gastric host. This review summarizes the functional and molecular regionalization of the stomach at homeostasis and details how chronic inflammation can lead to characteristic alterations in these developmental demarcations, both at the topographic and glandular levels. More importantly, this review illustrates our current understanding of the epithelial mechanisms that underlie the pre-malignant gastric landscape, how Hp adapts to and exploits these changes, and the clinical implications of identifying these changes in order to stratify patients at risk of developing gastric cancer, a leading cause of cancer-related deaths worldwide.

IL13 Acts Directly on Gastric Epithelial Cells to Promote Metaplasia Development During Chronic Gastritis

BACKGROUND & AIMS

It is well established that chronic inflammation promotes gastric cancer-associated metaplasia, but little is known regarding the mechanisms by which immune cells and cytokines regulate metaplastic cellular changes. The goals of this study were to identify interleukin 13 (IL13)-producing immune cells, determine the gastric epithelial cell response(s) to IL13, and establish the role(s) of IL13 in metaplasia development.

METHODS

Experiments used an established mouse model of autoimmune gastritis (TxA23), TxA23×Il4ra-/- mice, which develop gastritis but do not express the IL4/IL13-receptor subunit IL4Rα, and TxA23×Il13-Yfp mice, which express yellow fluorescent protein in IL13-producing cells. Flow cytometry was used to measure IL13 secretion and identify IL13-producing immune cells. Mouse and human gastric organoids were cultured with IL13 to determine epithelial cell response(s) to IL13. Single-cell RNA sequencing was performed on gastric epithelial cells from healthy and inflamed mouse stomachs. Mice with gastritis were administered IL13-neutralizing antibodies and stomachs were analyzed by histopathology and immunofluorescence.

RESULTS

We identified 6 unique subsets of IL13-producing immune cells in the inflamed stomach. Organoid cultures showed that IL13 acts directly on gastric epithelium to induce a metaplastic phenotype. IL4Rα-deficient mice did not progress to metaplasia. Single-cell RNA sequencing determined that gastric epithelial cells from IL4Rα-deficient mice up-regulated inflammatory genes but failed to up-regulate metaplasia-associated transcripts. Neutralization of IL13 significantly reduced and reversed metaplasia development in mice with gastritis.

CONCLUSIONS

IL13 is made by a variety of immune cell subsets during chronic gastritis and promotes gastric cancer-associated metaplastic epithelial cell changes. Neutralization of IL13 reduces metaplasia severity during chronic gastritis.

Glucocorticoids and Androgens Protect From Gastric Metaplasia by Suppressing Group 2 Innate Lymphoid Cell Activation

BACKGROUND & AIMS

The immune compartment is critical for maintaining tissue homeostasis. A weak immune response increases susceptibility to infection, but immune hyperactivation causes tissue damage, and chronic inflammation may lead to cancer development. In the stomach, inflammation damages the gastric glands and drives the development of potentially preneoplastic metaplasia. Glucocorticoids are potent anti-inflammatory steroid hormones that are required to suppress gastric inflammation and metaplasia. However, these hormones function differently in males and females. Here, we investigate the impact of sex on the regulation of gastric inflammation.

METHODS

Endogenous glucocorticoids and male sex hormones were removed from mice using adrenalectomy and castration, respectively. Mice were treated with 5α-dihydrotestosterone (DHT) to test the effects of androgens on regulating gastric inflammation. Single-cell RNA sequencing of gastric leukocytes was used to identify the leukocyte populations that were the direct targets of androgen signaling. Type 2 innate lymphoid cells (ILC2s) were depleted by treatment with CD90.2 antibodies.

RESULTS

We show that adrenalectomized female mice develop spontaneous gastric inflammation and spasmolytic polypeptide-expressing metaplasia (SPEM) but that the stomachs of adrenalectomized male mice remain quantitatively normal. Simultaneous depletion of glucocorticoids and sex hormones abolished the male-protective effects and triggered spontaneous pathogenic gastric inflammation and SPEM. Treatment of female mice with DHT prevented gastric inflammation and SPEM development when administered concurrent with adrenalectomy and also reversed the pathology when administered after disease onset. Single-cell RNAseq of gastric leukocytes revealed that ILC2s expressed abundant levels of both the glucocorticoid receptor (Gr) and androgen receptor (Ar). We demonstrated that DHT treatment potently suppressed the expression of the proinflammatory cytokines Il13 and Csf2 by ILC2s. Moreover, ILC2 depletion protected the stomach from SPEM development.

CONCLUSIONS

Here, we report a novel mechanism by which glucocorticoids and androgens exert overlapping effects to regulate gastric inflammation. Androgen signaling within ILC2s prevents their pathogenic activation by suppressing the transcription of proinflammatory cytokines. This work revealed a critical role for sex hormones in regulating gastric inflammation and metaplasia.